关键词: 变量, 喷雾, 靶标探测, 作物形貌, 冠层, 病虫害

Abstract: Spray control is the most common pest control method at present，and the technology is developing towards higher precision and intelligence. Accurate detection of targets is the key link of variable spray. In order to clarify the development level of variable spray detection technology at the present stage, the methods of target location detection, target contour volume detection, target canopy density detection and pest degree detection in variable spray technology are summarized. At the same time, it is introduced that infrared technology has better accuracy in target position detection. The accuracy of LiDAR technique is better than ultrasonic technique in detecting target contour volume and density. In terms of detecting pests and diseases the image processing technology is very accurate and the electronic nose technology is still in the laboratory stage. Finally, it is pointed out that it is still difficult to detect the density of crop canopy branches and leaves in the detection of variable spray targets by comparing the research status of related fields at home and abroad. The fusion detection technology of multiple sensors is proposed as an important direction of target technology detection in the future，which provides the technical basis for precision drug application technology and mechanical plant protection equipment.

Key words:  variable, sprays, target detection, crop morphology, crown layer, pests and diseases